CN101151203A - Elevator system - Google Patents

Abstract

The invention concerns a device, a method and a system for improving the safety system of an elevator. The safety system of the invention comprises an electric safety device, which monitors the velocity and position of the elevator in the elevator shaft. The safety device is e.g. a computer that is able to stop the elevator, using the brake of the hoisting machine or an optional car brake. The basic idea of the safety system of the invention is to form a continuous limit curve for control of elevator speed. The limit curve defines the limits of allowed elevator motion, which are determined on the basis of the nominal speed of the elevator and the location of the car. The safety system of the invention comprises measuring means for continuous measurement of elevator motion data and a safety device that receives data about the motion of the elevator, calculates its velocity at each instant of time utilizing the elevator motion data and watches the elevator motion to ensure that it remains within the allowed limit curve. Moreover, the safety system comprises a stopping device for stopping uncontrolled motion of the car if the elevator motion exceeds the limit curve set for it.

Description

elevator system

technical field

The invention relates to an elevator safety system. In particular, the invention relates to a safety device making it possible to integrate elevator safety functions.

Background technique

An important purpose of an elevator system is to maximize passenger safety. The elevator car must never be allowed to fall freely, and its motion must never reach an uncontrolled acceleration of motion or an uncontrolled deceleration of motion. Therefore, the elevator installation comprises several different safety and stopping devices which are concerned with stopping the elevator car in normal and fault situations.

Elevator control systems involve driving elevators between floors. During normal operation, acceleration and deceleration, the elevator control system involves eg slowing down the elevator and stopping the elevator at the correct floor. The control system also smoothly stops the elevator at the terminal floor. If the normal stop of the elevator by the control system does not work, the smooth stop of the elevator at the terminal floor is handled by the normal terminal deceleration (NTS: Normal Terminal Slowdown) function.

If the normal terminal deceleration (NTS) function cannot stop the elevator when the elevator reaches the end of the elevator shaft, the elevator is stopped by the emergency terminal speed limiting (ETSL) function by using the elevator's machine brake. The machine brake is an electromechanical brake, which is generally arranged to engage the traction sheave of the elevator when necessary. If the deceleration of the elevator is insufficient, ETSL can additionally use the brakes of the elevator car or wedge brakes, ie safety gears, to stop the elevator.

Figure 1 illustrates the operation of a safety device of an existing elevator system. Curve 10 represents the elevator motion as a function of distance and speed.

The safety device used may be a mechanical overspeed governor (OSG: overspeed governor). The overspeed governor monitors the speed of the elevator car in the elevator shaft and if the speed of the elevator car exceeds a given preset limit value (for example 6 m/s), the overspeed governor will cause the safety circuit of the elevator to break ON to engage the machine brake (area 12). The elevator has a safety circuit that is opened when one of the switches connected to it is opened. If the overspeed still continues to increase, the overspeed governor will operate the safety gear (area 16) provided in conjunction with the elevator car, the safety gear sprag engages the elevator guide rail and prevents the elevator car from moving. In other words, if one or more rope suspensions fail and the elevator car begins to free fall, the safety gear will wedge and jam.

A final limit switch is arranged near the end of the elevator shaft. The position of the last limit switch is indicated by x1 in FIG. 1 . If the elevator has not stopped before reaching the last limit switch, the elevator safety circuit is opened again and the brake of the elevator is activated. The final limit switch uses the machine brake (range 12) to stop the elevator car if the elevator advances eg 100mm beyond the final position.

If the elevator moves a few centimeters beyond the last limit switch, the car (or the corresponding counterweight) will hit the buffer 13 which will finally stop the elevator by elastic action. Even after said buffer there must be a space 14 after which the elevator will touch the concrete end structure 15 of the elevator shaft.

Even if the normal control system fails, it is safe in principle for multiple full-sized buffers to have sufficient stroke length to run onto the buffers at full speed, without exceeding the acceleration in the elevator car before the elevator car comes to a stop. allowed limit. Generally, 1g is an acceleration/deceleration altitude defined in safety regulation as a value that can be tolerated by humans.

Figure 2 illustrates the operation of the safety system of an elevator when the elevator system uses a so-called reduced-stroke buffer 23 . After the buffer 23 there is a space 24 which is close to the concrete end structure 25 of the elevator shaft. In this case, an electronic safety circuit is used to achieve the stopping of the elevator car. At some distance from the end of the elevator shaft a switch is installed with a speed limit of eg 90% of the rated speed (switch 2 and switch 3). Another switch (Switch 1 and Switch 4) with a speed limit of eg 60% of rated speed is installed close to the end of the elevator shaft. If the speed exceeds 90% of the rated speed at the switches (switch 2 and switch 3), the safety circuit will open again and the machine brake (zone 22) will stop the elevator car. If the speed exceeds 60% of rated speed at the switches (switch 1 and switch 4), the safety circuit will open and the machine brake will stop the elevator car (zone 22). If the overspeed still increases from that height, the elevator's safety system will stop the car using the safety gear provided in conjunction with the elevator car (area 26).

Authorities in different countries have different regulations regarding elevator safety. The basic principle is that the elevator should have

There are safety systems capable of stopping the elevator in case of failure. For example, according to the European Union's Lift Directive 95/16/EC, lifts should have an overspeed governor and a speed monitoring system. The elevator must not achieve uncontrolled acceleration of motion or uncontrolled deceleration of motion. In addition, in the elevator shaft, there must be a buffer and a sufficient safety space between the elevator car and the end of the elevator shaft.

When upgrading elevators in older buildings, problems often arise because safety regulations have changed over time and there is not enough space in the elevator shaft above and below the elevator car as required by current safety regulations. As far as structural engineering is concerned, extending elevator shafts upwards or downwards is in most cases impossible, or at least expensive and difficult to the point of being impossible.

Contents of the invention

The purpose of the present invention is to disclose a new type of elevator safety system which will perform the functions of several different safety devices, thus reducing the number of safety devices and increasing the reliability of the safety system. A specific object of the invention is to ensure an overspeed governor as required by effective safety regulations and a sufficiently large safety space at the top and bottom of the elevator shaft.

The method, device and system of the invention are characterized by what is disclosed in claims 1 , 10 and 19 . Other embodiments of the invention are characterized by what is disclosed in the other claims. Inventive embodiments are also provided in the descriptive section and drawings of the present application. The inventive content disclosed in this application may also be defined in other ways than in the claims below. The inventive content can also consist of several separate inventions, if the invention is considered in the light of explicit or implicit sub-tasks or advantages or groups of advantages achieved. In this case, some of the attributes contained in the following claims may be superfluous from the point of view of independent inventive concepts. Within the framework of the basic idea of the invention, features of different embodiments of the invention can be applied in combination with other embodiments.

With regard to the features of the invention, see the claims.

The present invention relates to devices, methods and systems for improving the safety system of elevators.

The safety system according to the invention comprises an electronic safety device which monitors the speed and position of the elevator in the elevator shaft. The security device is, for example, a computer with two independent processors. Each processor is capable of independently stopping the elevator using the hoist or optional car brakes.

The basic idea of the elevator safety system of the invention is to form a continuous limit curve for controlling the speed of the elevator. The limit curves define the limits of allowed elevator movement, which limits are determined from the rated speed of the elevator and the position of the car. In said new safety system, the speed, direction and distance from the end of the elevator shaft are also continuously monitored in the terminal deceleration range.

The safety system of the present invention comprises: a measuring part for continuously measuring elevator motion data; and a safety device which receives data about the motion of the elevator, uses the elevator motion data to calculate the velocity at each moment thereof, and views the elevator motion To ensure that it remains within the allowable exercise limit curve. Furthermore, the safety system includes stopping means to stop uncontrolled car movement if the elevator moves beyond the limit curve set for it.

In one embodiment of the invention, the limit curves provided for the movement of the elevator comprise two separate limit curves. If the elevator moves beyond the first limit curve, the safety device of the elevator safety system will stop the elevator car using a machine brake for braking the rotation of the elevator's traction sheave, motor or motor shaft. If the overspeed situation continues and the elevator moves beyond the second limit curve, the safety device of the elevator safety system will stop the elevator car using a safety gear, which is connected to the overspeed governor rope and engages the elevator guide rail.

In one embodiment of the present invention, the safety device of the elevator safety system includes at least one connection interface for receiving elevator movement data. The elevator movement data comprise data about the position of the elevator in the elevator shaft and/or data about the acceleration of the elevator in the elevator shaft. Furthermore, the safety device may comprise at least one connection interface for receiving door zone data, data about maintenance operating modes, and/or data about the status of the safety circuit.

In the maintenance mode of operation, when maintenance personnel are on top of the elevator car, sufficient safety space needs to be provided at the upper end of the elevator shaft to ensure safe working conditions. The size of the safety space can be reduced by using a new safety device, since in the maintenance mode of operation said safety device stops the elevator car by activating the electromechanical brake eg 1.4 meters before the end of the elevator shaft. If the electromechanical brake fails to stop the elevator, the safety device may activate a double-way safety gear eg 1.2 meters before the end of the elevator shaft. Near the pit of the elevator shaft, the position of the last limit switch can be changed in the same way, actuating the electromechanical brake at 1.4 meters from the end and at 1.2 meters from the end activate the safety gear. The lift cannot reach the bottom of the lift shaft, so there is a 1.2 meter safe space left under the lift.

This safety function in the maintenance mode of operation is particularly beneficial in the reality that there is not enough safety space in old elevator shafts. For example, in Europe there are many elevators in which the space above/under the elevator car does not meet the current latest elevator safety regulations. By using the safety device it is possible to bring the safety space of even old elevators into compliance with the latest safety regulations.

Advantages of the invention relate to improved elevator safety and facilitated retrofitting of old elevators. The device of the invention does not per se reduce fault conditions in elevator systems, but it can be used to improve the reliability and coverage of safety systems, and to facilitate retrofitting of old elevators so that they comply with new safety regulations. Another advantage is the structural simplicity of the device by using existing braking devices, so that it can be easily installed in existing old elevators without any major and expensive modifications.

By using the new safety device, the size of the buffers of the elevator can be reduced considerably compared to the present. The safety device of the invention allows reducing the number of devices required for installation. Security can be centralized in one location. The safety device of the invention is designed to integrate several safety functions in a single component. Therefore, while reducing the number of devices to be installed, it is not necessary to install each safety device independently.

In new elevators, suitable devices are used to implement the safety system described above, which can in principle also be used in older elevators already in use. However, this would require major changes and additions to the old elevator structure, so the elevator would have to be completely re-examined. In practice, the entire elevator needs to be renewed to such an extent that it is more economical to build a completely new elevator when evaluated in the long term.

Description of drawings

Below, the present invention will be described in detail with reference to the examples of embodiment, wherein:

Figures 1 and 2 illustrate the operation of prior art safety devices,

Figure 3 shows an embodiment of a security system according to the invention;

Figure 4 shows an embodiment of the safety curve of the safety device and the operation of the safety device according to the invention; and

Figure 5 shows an embodiment of the operation of the safety device in a maintenance mode of operation.

Detailed ways

Figure 3 illustrates in simplified form the operation of the security system of the present invention. In this simplified example, safety device 301 includes two separate processors 302 and 303 that monitor the speed and position of the elevator car in the elevator shaft. The safety device has an interface 30 for receiving door zone data and data provided by the acceleration sensor. In addition, the safety device has interfaces 31 and 32 for detecting the maintenance mode of operation and the state of the safety circuit. The control system and control logic 37 of the elevator is used to control the movement of the elevator car 36 between floors and to stop the elevator at a terminal floor via a normal terminal slowdown (NTS) function.

Each processor 302 and 303 independently receives data regarding the absolute position of the elevator car and door zone data specifying the precise location of the door zone for each floor. The positioning elements for positioning the elevator can be, for example, the same two USP30 or UPS100 positioning systems from Schmersal AG.

The locating device may also contain some other two-channel means to provide an absolute position such as a two-channel laser measurement obtained from motor speed and floor codes obtained from tapes provided on each floor, Ultrasonic measurements or elevator position data.

In the USP position measurement system, the transmitter 313 is mounted on the elevator car 36 and the receivers are mounted on the bottom 35 and the upper end 34 of the elevator shaft. The transmitter and receiver are connected by a signal lead 38 into which the transmitter injects ultrasonic pulses. The receiver measures the time elapsed during the propagation of the ultrasonic pulse and determines the position of the elevator car from it. The distance from the elevator car to both the upper end and the lower end of the elevator shaft is obtained when the ultrasonic pulses propagate from the transmitter along the signal leads in both directions. The sum of these two measurements d1 and d2 must remain constant. In other words, if one of the channels starts generating erroneous data, the processors 302 and 303 of the security device will detect this immediately.

If the sum of d1 and d2 is incorrect or if one of the two measurements is lost altogether, the safety device 301 will go into an alert mode. In said alert mode the speed of the elevator car is limited to the maintenance operating speed and the safety device calculates this speed and position from two acceleration sensors mounted on the elevator car. If the safety device does not receive data from the acceleration sensor about the speed and position of the elevator car, it will not allow the elevator to move. In this case, maintenance personnel need to manually make a connection in the system using a jumper wire to allow the elevator to move. Alternatively, the brakes can be released manually to allow the elevator to move to the level of the floor.

During the pointing operation, the safety device is informed of the precise position of the floor. During pointing operations, the elevator is positioned at the lowest or highest floor and then driven end-to-end, the safety device thus knowing the precise location of the floor from the door zone sensor.

Although the example in Figure 3 shows a security device comprising a dual scheme (two independent processors). In other embodiments of the invention, however, it is also possible to use solutions in which the operation of the safety device is not necessarily doubled. Similarly, any suitable means may be used to determine the position of the elevator in the elevator shaft.

Figure 4 shows a limit curve 49 of the safety device of the invention during normal operation. Curve 400 represents elevator travel as a function of distance and time. The figure shows two limit curves 49 and 410 according to an example of the invention. The region 48 between the curve 400 and the first limit curve 49 is an intermediate region in which the safety braking has not yet been activated. The safety device continuously calculates the speed of the elevator from the elevator position data supplied into the input channel. If said speed exceeds a given predetermined speed of 6 m/s (curve 49), the safety device opens the safety circuit and applies the machine brakes (area 42). If the overspeed still continues thereafter (curve 410), the safety device will use the safety gear or the independent car brake to stop the elevator (area 46).

If the elevator moves to a few centimeters behind the last limit switch, the car (or similar counterweight) will hit the buffer 43 which finally stops the elevator by elastic action. Even after the buffer there must be a space 44 after which the elevator will hit the concrete end structure 45 of the elevator shaft.

FIG. 5 shows the limit curve of the safety device in the maintenance mode of operation. The processor of the safety device receives data indicating whether the elevator is in a maintenance mode of operation, ie data indicating whether the safety space and overspeed of the elevator are to be restricted. The elevator system enters into a maintenance operation mode, for example if a maintenance person presses a mushroom-shaped button at the bottom of the elevator shaft or uses an operating switch for maintenance operations arranged at the top of the elevator car. In this case, the safety device will start to limit the distance from the bottom and top of the elevator shaft and impose a speed limit according to the maintenance operation speed.

According to safety regulations, in Europe the speed limit during maintenance operations is 0.63 m/s, while in the US and Canada it is 0.75 m/s. If the maintenance mode of operation is active, the safety device will try to keep the rated speed of the elevator car not to exceed eg 0.75 m/s. For maintenance operations, a sufficient speed limit is 0.75 m/s, since in Europe, at least currently, no mandatory stops are required during maintenance operations. If the safety device has detected that the elevator system is in a maintenance mode of operation, the last limit switch will be moved to say 1.4 meters from the end of the elevator shaft, thus automatically leaving a larger compression space at the end of the elevator shaft, i.e. Safe space for maintenance personnel. If the speed of the elevator car exceeds the speed allowed during maintenance operations (0.75 m/s), the safety device will immediately stop the car near the end of the elevator shaft, using the machine brake, the nearest 1.2 meters before the end of the elevator shaft (area 52).

Safe when the speed of the elevator car exceeds 1.0 m/s and the nearest 1.2 m before the end of the elevator shaft if there is a fault situation in the machine brake or if the friction between the hoisting rope and the traction sheave of the elevator disappears The device will stop the elevator car through the safety gear (area 56). When the last limit switch is displaced to a remote position away from the end of the elevator shaft, the space occupied by the elevator in the building can be reduced and safe elevator operation is achieved.

Each processor of the safety device receives data indicating whether the safety circuit is not broken, ie whether the elevator is in an operating condition. If the safety circuit breaks, the safety device will detect this immediately, engage the machine brakes, and stop the elevator car. If the machine brake does not hold or if there is no friction between the hoisting ropes and the traction sheave (fault in the hoisting system or the brakes), the safety device will be able to activate the two-way safety gear provided on the elevator car, so the elevator can still run It stops before reaching the buffer. The safety device can also control other elevator car brakes which will stop the movement of the elevator car independently of the ropes and machine brakes.

If the elevator moves forward a few centimeters beyond the last limit switch, the elevator car (or similar counterweight) will hit the buffer 53, which will finally stop the elevator by elastic action. Even after the buffer there must be a space 54 after which the elevator will hit the concrete end structure 55 of the elevator shaft.

It is obvious to a person skilled in the art that the invention is not limited to the embodiments described above, in which the invention is illustrated, but that it can be found within the scope of the inventive idea defined in the appended claims below. There are many variations and different embodiments of the invention.

Claims (27)

1. A method for improving elevator safety, characterized in that the system comprises: A measuring component for continuously measuring elevator movement data; A safety device arranged to receive data about the movement of the elevator, use the elevator movement data to calculate its velocity at each moment, look at the movement of the elevator to ensure it remains within the allowed movement limit curve, and if the movement of the elevator exceeds For the limit curve provided therefor, at least one stopping device is actuated to stop uncontrolled carriage movements. 2. The security system according to claim 1, characterized in that: The limit curve determines the speed limit of the allowed elevator movement at each instant, which speed limit depends on the rated speed of the elevator and its position in the elevator shaft. 3. Security system according to claim 1 or 2, characterized in that: The limit curves comprise two separate limit curves. 4. The security system according to claim 3, characterized in that: When the elevator moves beyond a first limit curve, the safety device is arranged to activate a first stopping device; and The safety device is arranged to activate a second stopping device when the elevator moves beyond a second limit curve. 5. The security system according to claim 4, characterized in that: The first stopping device is a device for braking the rotation of the traction sheave, the motor or the motor shaft of the elevator. 6. Security system according to claim 4 or 5, characterized in that: The second stopping device is a safety gear or other corresponding car brake connected to an overspeed governor rope and engaging the elevator guide rail. 7. Security system according to any one of the preceding claims 1-6, characterized in that: The safety device comprises at least one connection interface for receiving elevator movement data. 8. A security system according to claim 7 or 5, characterized in that: The movement data comprise data about the position of the elevator in the elevator shaft and/or data about the acceleration of the elevator in the elevator shaft. 9. Security system according to any one of the preceding claims 1-8, characterized in that: The safety device comprises at least one connection interface for receiving door zone data, data about maintenance operating modes, and/or data about the status of the safety circuit. 10. A safety device for improving elevator safety, characterized in that the safety device comprises: At least one connection interface for receiving elevator position data; means for calculating the speed of said elevator from elevator car position data; means for monitoring the speed in order to maintain the speed of the elevator using an allowed movement limit profile; and Components for controlling at least one stopping device if the elevator moves beyond a permissible movement limit curve set for it. 11. Safety device for improving elevator safety according to claim 10, characterized in that, The limit curve determines at each instant the speed limit of the allowed elevator movement, which speed limit depends on the rated speed of the elevator and its position in the elevator shaft. 12. Safety device according to the preceding claim 10 or 11, characterized in that, The limit curves comprise two separate limit curves. 13. A safety device according to claim 12, characterized in that, When the elevator moves beyond a first limit curve, the safety device is arranged to activate a first stopping device; and The safety device is arranged to activate a second stopping device when the elevator moves beyond a second limit curve. 14. A safety device according to claim 13, characterized in that, The first stopping device is a device that brakes the rotation of the traction sheave, the motor or the motor shaft of the elevator. 15. Safety device according to claim 13 or 14, characterized in that, The second stopping device is a safety gear or other corresponding car brake connected to an overspeed governor rope and engaging the elevator guide rail. 16. A safety device according to any one of the preceding claims 10-15, characterized in that, The safety device comprises at least one connection interface for receiving elevator movement data. 17. A safety device according to any one of the preceding claims 10-16, characterized in that, The motion data comprise data about the position of the elevator in the elevator shaft and/or data about the acceleration of the elevator in the elevator shaft. 18. Safety device according to any one of the preceding claims 10-17, characterized in that said safety device comprises: At least one connection interface for receiving door zone data, data about maintenance operating modes and/or data about the status of said safety circuit. 19. A method for improving the safety system of an elevator, characterized in that said method comprises the steps of: Continuously measure the movement of the elevator in the elevator shaft; calculating the speed of the elevator car based on the elevator motion data; using safety devices to control the movement of the elevator to ensure that it remains within the allowed movement limit curve; and The safety device stops the elevator using at least one stopping device if the elevator moves beyond a limit of permissible movement set according to the limit curve. 20. The method according to claim 19, characterized in that, The limit curve determines the speed limit of the allowed elevator movement at each instant, which speed limit depends on the rated speed of the elevator and its position in the elevator shaft. 21. A method according to claim 19 or 20, characterized in that, The limit curves comprise two separate limit curves. 22. The method according to claim 21, characterized in that, activating the first stopping device if the elevator movement exceeds the first limit curve; and If the elevator moves beyond a second limit curve, a second stopping device is activated. 23. The method according to claim 22, characterized in that, The first stopping device is a device that brakes the rotation of the traction sheave, the motor or the motor shaft of the elevator. 24. A method according to claim 22 or 23, characterized in that, The second stopping device is a safety gear or other corresponding car brake connected to an overspeed governor rope and engaging the elevator guide rail. 25. A method according to any one of the preceding claims 19-24, characterized in that, Data about the movement of the elevator is transmitted to the safety device. 26. The method according to claim 25, characterized in that, The data about the movement of the elevator transmitted to the safety device comprises data about the position of the elevator in the elevator shaft and/or data about the acceleration of the elevator in the elevator shaft. 27. A method according to any one of the preceding claims 19-26, characterized in that, Door zone data, data on maintenance operating modes and/or data on the status of the safety circuit are transmitted to the safety device.

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